二溴新戊二醇在膨胀型阻燃乙烯-醋酸乙烯酯共聚物中的作用机理

Flame Retardant Mechanism of Dibromoneopentyl Glycol in Intumescent Flame Retardant/Ethylene-Vinyl Acetate Copolymer System

以季戊四醇(PER)/二溴新戊二醇(DBNPG)混和磷酸酯三聚氰胺甲醛树脂(MFR)微胶囊化聚磷酸铵(APP)合成膨胀型阻燃剂(IFR)。研究了DBNPG的含量在膨胀型阻燃乙烯-醋酸乙烯酯共聚物(EVA)中的影响。流变行为、热分析、扫描电镜、阻燃性能与膨胀度测试结果表明:DBNPG可以通过改善炭层的膨胀度、致密度和封闭性来提高隔热性能。适当的DBNPG可改善IFR与EVA的相容性,增大熔体的黏度,形成封闭的炭层,提高炭层的隔热性能,降低燃烧体系放热,有利于阻燃性能的提高。但DBNPG含量过高,会降低流体的黏度,恶化炭层的隔热性能,放热量增大,阻燃性能降低。当IFR中DBNPG/PER的质量比为38.5/90.0,EVA/IFR的质量比为70/30时,复合材料具有最佳的阻燃性能和良好的力学性能。

Based on ammonium polyphosphate(APP) microencapsulated with pentaerythritol(PER)/dibromoneopentyl glycol(DBNPG) mixed phosphate melamine salt as intumescent flame retardant(IFR),the influence of DBNPG on flame-retarded ethylene-vinyl acetate copolymer was investigated. The results of rheological behavior,thermal analysis,SEM,intumescent degree and property test prove that the intumescent degree,compactness and closeness of char layer are determinants of the thermal barrier property. Appropriate DBNPG content can improve the compatibility of IFR and EVA,increase the melting viscosity of composites,promote the formation of closed char layer,contribute to better thermal barrier property,decrease the combustion heat,and all of these are beneficial to the flame retardancy of IFR/EVA. However,excessive DBNPG content will decrease the melting viscosity of composites,destroy the closure of char layer,deteriorate the thermal barrier property,and increase the combustion heat,as a result the flame retardancy of the IFR/EVA is weakened. When the mass ratio of DBNPG/PER is 38. 5/90. 0,and the mass ratio of EVA/IFR is 70/30, the composite exhibits optimal fire resistance and excellent mechanical property.